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相关论文: Constraints on Compact Hyperbolic Spaces from COBE

200 篇论文

Geometric characteristics of random fields are exploited to test the consistency of density perturbation model spectra with COBE data. These CMB maps are analyzed using the number of anisotropy hot spots and their boundary curvature. CMB…

天体物理学 · 物理学 2008-02-03 Sergio Torres

We show how observations of temperature fluctuations in cosmic microwave background (CMB) can be used to extract information related to the large scale structure, including dark matter distribution, pressure and halo velocities involving…

天体物理学 · 物理学 2007-05-23 Asantha Cooray

We analyse the anisotropy of the cosmic microwave background (CMB) in hyperbolic universes possessing a non-trivial topology with a fundamental cell having an infinitely long horn. The aim of this paper is twofold. On the one hand, we show…

天体物理学 · 物理学 2009-11-10 Ralf Aurich , Sven Lustig , Frank Steiner , Holger Then

We discuss the problem of CMB spectrum corruption during Galactic emission removing. A new technique of spatial--frequency data reduction is proposed. The technique gives us a possibility to avoid a spatial harmonics nonorthogonality. The…

天体物理学 · 物理学 2007-05-23 A. A. Brukhanov , D. P. Skulachev , I. A. Strukov , T. V. Konkina

The Cosmic Microwave Background (CMB) reaches homogeneity at relatively modest angular scales compared to the expectation of the standard $\Lambda$CDM model revealing an important challenge to the theoretical predictions. We analyze this…

Recent analyses of the WMAP data have suggested that the low-order multipoles of the CMB anisotropy distribution show cosmologically interesting and unexpected morphologies and amplitudes. In this paper, we apply a power equalization (PE)…

天体物理学 · 物理学 2009-11-10 P. Bielewicz , K. M. Gorski , A. J. Banday

The COBE satellite has discovered anisotropies in the cosmic microwave background (CMB) consistent with a scale invariant spectrum of density perturbations. As reviewed in this lecture, topological defect models of structure formation…

高能物理 - 唯象学 · 物理学 2007-05-23 Robert H. Brandenberger

Spatial correlations of the cubic 3-torus topology are analysed using the Planck 2013 data. The spatial-correlation method for detecting multiply connected spaces is based on the fact that positions on the cosmic microwave background (CMB)…

宇宙学与河外天体物理 · 物理学 2015-08-06 R. Aurich

We report and analyse the presence of foregrounds in the cosmic microwave background (CMB) radiation associated to extended galactic halos. Using the cross correlation of Planck and WMAP maps and the 2MRS galaxy catalogue, we find that the…

宇宙学与河外天体物理 · 物理学 2026-03-19 Heliana E. Luparello , Ezequiel F. Boero , Marcelo Lares , Ariel G. Sánchez , Diego García Lambas

We show that a good fitting to the first two years of {\it COBE}-DMR observations of the two-point angular correlation function of CBR temperature is given by models with a non-zero infrared cutoff $k_{min}$ in the spectrum of the…

天体物理学 · 物理学 2009-10-22 Yi-Peng Jing , Li-Zhi Fang

The current suite of results from Cosmic Microwave Background anisotropy experiments is fulfilling the promise of providing extraordinary levels of discrimination between cosmological models. We calculate a binned anisotropy power spectrum,…

天体物理学 · 物理学 2007-05-23 Elena Pierpaoli , Douglas Scott , Martin White

To date, no compelling evidence has been found that the universe has non-trivial spatial topology. Meanwhile, anomalies in the observed CMB temperature map, such as the lack of correlations at large angular separations, remain…

宇宙学与河外天体物理 · 物理学 2018-09-18 Armando Bernui , Camila P. Novaes , Thiago S. Pereira , Glenn D. Starkman

We present a new data analysis method to study rectangular T^3 ``small universes" with one or two of its dimensions significantly smaller than the present horizon (which we refer to as T^1- and T^2-models, respectively). We find that the 4…

天体物理学 · 物理学 2007-05-23 Angelica de Oliveira-Costa , George F. Smoot , Alexei A. Starobinsky

We propose an alternative formalism to simulate CMB temperature maps in $\Lambda$CDM universes with nontrivial spatial topologies. This formalism avoids the need to explicitly compute the eigenmodes of the Laplacian operator in the spatial…

天体物理学 · 物理学 2008-11-26 W. S. Hipolito-Ricaldi , G. I. Gomero

We discuss the algorithmic information approach to the analysis of the observational data on the Universe. Kolmogorov complexity is proposed as a descriptor of the Cosmic Microwave Background (CMB) radiation maps. An algorithm of…

天体物理学 · 物理学 2017-08-23 V. G. Gurzadyan

Measurements of the cosmic microwave background (CMB) temperature anisotropies have revealed a dipolar asymmetry in power at the largest scales, in apparent contradiction with the statistical isotropy of standard cosmological models. The…

宇宙学与河外天体物理 · 物理学 2018-03-07 D. Contreras , J. Hutchinson , A. Moss , D. Scott , J. P. Zibin

The degree of randomness in the cosmic microwave background (CMB) maps has been shown to be measurable and indicative of the hyperbolic effect of voids on the propagation of the photon beams. In terms of an introduced porosity parameter, we…

天体物理学 · 物理学 2009-11-13 V. G. Gurzadyan , A. A. Kocharyan

We examine the degree to which observations of large-scale cosmic microwave background (CMB) polarization can shed light on the puzzling large-scale power modulation in maps of CMB anisotropy. We consider a phenomenological model in which…

宇宙学与河外天体物理 · 物理学 2016-11-23 Emory F. Bunn , Qingyang Xue , Haoxuan Zheng

Density perturbations at the decoupling epoch produce angular fluctuations in the temperature of the Cosmic Microwave Background (CMB) radiation that may appear as hot and cold spots. Observational data of the CMB includes instrumental…

天体物理学 · 物理学 2009-10-28 Laura Cayon , George Smoot

First, we establish which measures of large-scale perturbations are least afflicted by gauge artifacts and directly map the apparent evolution of inhomogeneities to local interactions of cosmological species. Considering nonlinear and…

天体物理学 · 物理学 2007-05-23 Sergei Bashinsky